Luxating Patella Surgery for Dogs

Luxating patella injuries trouble small breed dogs. Basset Hounds, Boston terriers, Dachshunds, Lhasa Apsos, Pekingnese, Pomeranians and Toy Poodles remain breeds most likely to suffer from the painful dislocation of the knee cap.

Treatment for luxating patellas is limited to surgery. On rare occasions, physical therapy can help, but never with lasting results. It's best to have your vet check your dog at a young age to check for signs of luxating patella problems.

If you are determined to purchase a small breed dog, ask the breeder if the dogs have been checked for luxating patella disorder. Avoid purchasing a puppy from a breeder who does not check his dogs or whose dogs do have the condition.

Cause of a Luxating Patella

Luxated patella injuries occur two ways. In one, the ridged grove that holds the kneecap in place wears down. When the ridge wears down, the patella is able to slip out of place. With the other, the ligament that secures the tibia to the patella is improperly located. Either way, once the kneecap is out of alignment, the dog's leg cannot bed. As the muscle relaxes, the patella may slip back into place.

Even if the bone slips back into place, during exercise it can slip back out. The more this happens, the more the ridge wears down. Eventually arthritis sets in. The dog is left with a swollen knee and intense pain.

Grading the Luxating Patella

There are four grades used to determine the best treatment for a luxated patella.

• Grade 1: The veterinarian easily manipulates the kneecap out of place but when released it returns to the proper position.

• Grade 2: The veterinarian is able to move the kneecap out of position, but it doesn't return to the correct position when released.

• Grade 3: The kneecap is always out of proper alignment, but with manipulation it can be moved back into place.

• Grade 4: The kneecap simply will not stay in the right position.

Dogs with grade 1 rarely undergo surgery. With grade 2, veterinarians will give pet owners the option. Grades 3 and 4 require surgery.

Surgical Techniques to Repair a Luxating Patella

The surgical technique used to repair luxating patella conditions depends on the cause of the kneecap dislocation.

• Lateral Reinforcement is a surgical procedure where the joint holding the patella is tucked to tighten the joint capsule. By shrinking the area of the joint capsule, the patella is held in place.
• Trochlear Modification is a surgery where cartilage in the femur is peeled back. Once the cartilage is out of the way, a grove is cut into the femur bone. The deeper grove holds the patella in place. Once the bone is notched, the cartilage is put back in place.
• Tibial Crest Transposition is a surgical procedure used in severe luxated patellas where the tibia has rotated because of pressure from the out of place kneecap. The tibia has a crest where the thigh muscle attaches. This crest is removed and the muscle reattached so that the tibia is straightened. In some situations, a section of tibia bone may need to be removed and the bone may need to be manipulated into the proper alignment.